Use native javascript instead of babel

[PymZoR]

As Promises are now supported natively, there is no use of babel anymore.
In addition, promise warnings such as Warning: a promise was created in a handler but was not returned from it that were caused by babel / bluebird are now solved.

[nskazki]

Fair enough. Unfortunately, I just applied a bunch of massive changes to this repository.
Most likely it will be easier to re-apply all the changes you made manually than bother with merging considering the size of the repository. Will see what I can do.